def print_models(unprinted_designs, completed_models):
    while unprinted_designs:
       current_design = unprinted_designs.pop()
       print(f"Printing model: {current_design}")
       completed_models.append(current_design)


def show_completed_models(completed_models):
    print("\nThe following models have been printed:")
    for completed_model in completed_models:
       print(completed_model)
